Re: [APML]: 37 films tested

[Robert Reeves <rreeves@connecti.com>]

>   I find that P1600 falls off rapidly after about 16 minutes of exposure.  I 
>have also found that it works well at 1600 during the summer and at 800 
>during the winter.  Exposing it at 1600 does give a speed increase over 800 
>during warm weather.  In Alberta, where it gets damn cold, I would expose it 
>at 400 with good results.  In my opinion, the grain at 1600 is not so much 
>worse than the grain at 800 as to make it a bad option when the conditions 
>warrant the extra speed.
>   Clear skies!
>               MK
>
>http://www3.sympatico.ca/mark.kaye/
>

Actually, it already looses two f/stops of speed in the first two minutes
alone.  I did not do extended exposure tests on P1600, but on other films
the trend was the longer the exposure, the worse the reciprocity law losses
became.  When you start off with a 2 stop loss the first two minutes, you
are practically at a standstill by 16 minutes.

BTW, the only film I found (of those I did do extended exposure tests beyond
two minutes) that did not loose more speed with longer exposures was Royal
Gold 400.  It maintained a flat one f/stop speed loss at 2, 4, and 8 minutes.

I am almost through typing up all the film testing data.  Putting all those
numbers into HTML tables is taking far longer than I guessed it would.  I
should have it all on my web site by Saturday morning.

Robert Reeves                Home page http://www.connecti.com/~rreeves
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